Attachment assembly for firearm handguard and method of attaching handguard to a firearm

ABSTRACT

An attachment assembly for a firearm handguard includes a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon. The barrel nut includes a first end for engaging an upper receiver of a firearm, a second end opposite the first end for receiving the firearm handguard, and a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, which mechanically locks the firearm handguard on the barrel nut. The barrel nut can include an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver. A knurled section can be formed on the exterior surface between the transverse groove and the second end, which provides frictional engagement at the interface of the barrel nut and the handguard.

This application claims priority to U.S. Provisional Application No. 61/323,132, filed Apr. 12, 2010. The present invention relates to handguard attachment assembly for use on a firearm, and a method of attaching a handguard to a firearm. One embodiment of the invention is particularly suited for use with automatic and semi-automatic rifles, such as the M-16, AR-15 and AR-10 rifles.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

Handguards for use on firearms are known in the art for providing protection to the user from burns that can result from heat generated along the barrel of the firearm during use. While such handguards offer protection from the hot temperatures generated by firing of the weapon, the handguards can be prone to becoming loose or detached from the firearm due to the force generated when discharging the firearm. Also, the handguards can become loose or detached due to the rigorous handling of the firearm, such as use in combat related activities. Sudden unexpected detachment of the handguard from the firearm can render the firearm ineffective and can pose a risk of injury to the user, particularly in combat situations. Accordingly, there is a need for a means for attaching a handguard to a firearm that reliably and firmly maintains the handguard on the firearm in a fixed position and prevents it from becoming loose or detached during discharge or rigorous activity on the part of a user carrying the firearm.

SUMMARY OF THE INVENTION

Therefore, one object of the present invention is to provide a handguard with an attachment assembly that firmly maintains the handguard in a fixed position on the firearm during use. Another object of the invention is to provide a method of attaching a handguard to an automatic or semi-automatic firearm, such as an M-16, AR-15 or AR-10. These and other objects of the present invention can be achieved in the preferred embodiments of the invention described below, in which one embodiment comprises an attachment assembly for a firearm handguard comprising a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon. The barrel nut comprises a first end for engaging an upper receiver of a firearm, a second end opposite the first end for receiving the firearm handguard, and a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the transverse groove mechanically locks the firearm handguard on the barrel nut.

According to another embodiment of the invention, the barrel nut includes an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver.

According to another embodiment of the invention, the barrel nut threads are female threads, and the upper receiver threads are male.

According to another embodiment of the invention, the barrel nut has a length of 0.875 inch to 8.000 inches.

According to another embodiment of the invention, the barrel nut has a length of about two inches.

According to another embodiment of the invention, the barrel nut includes a knurled section formed on the exterior surface of the barrel nut proximate the second end, and the knurled section facilitates frictional engagement at the interface of the barrel nut and the handguard.

According to another embodiment of the invention, the transverse groove is formed on the exterior surface of the barrel nut between the first end and the knurled section, and the knurled section is formed on the exterior surface between the transverse groove and the second end.

According to another embodiment of the invention, an attachment assembly for a firearm comprises a firearm handguard having an elongate rail section for a user to grip the handguard, an open exit end for allowing a firearm barrel to exit therethrough, and an open receiving end opposite the exit end for positioning over a barrel nut mounted on a firearm barrel, and mating with an upper receiver of the firearm. A lug is formed on the receiving end such that the lug provides a mechanical, anti-rotation lock when the handguard interfaces with the upper receiver.

According to another embodiment of the invention, the lug is formed in the receiving end at a depth of about 0.125 inch.

According to another embodiment of the invention, the attachment assembly includes a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon. The barrel nut includes a first end for engaging an upper receiver of a firearm, a second end for receiving the firearm barrel and the firearm handguard; and a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, which mechanically locks the firearm handguard on the barrel nut.

According to another embodiment of the invention, the barrel nut includes an interior surface with threads formed thereon proximate the first end for engaging complementary threads on the upper receiver.

According to another embodiment of the invention, the barrel nut includes a knurled section formed on the exterior surface of the barrel nut proximate the second end, and the knurled section facilitates frictional engagement at the interface of the barrel nut and the handguard.

According to another embodiment of the invention, the transverse groove is formed on the exterior surface of the barrel nut between the first end and the knurled section, and the knurled section is formed on the exterior surface between the transverse groove and the second end.

According to another embodiment of the invention, at least one cavity is formed in the rail section of the handguard proximate the receiving end, and the cavity is threaded to receive and mate with a complementary threaded fastener, such that the fastener frictionally engages the barrel nut and provides a mechanical mounting lock.

According to another embodiment of the invention, an exterior surface of the cavity is comprised of aluminum, and the complementary threaded fastener comprises a steel quick disconnect thumbscrew insert.

According to another embodiment of the invention, a quick disconnect sling is attached to the quick disconnect thumbscrew insert.

According to another embodiment of the invention, a first pair of cavities are formed on opposite sides of the rail section proximate the receiving end. The cavities are counterbored and threaded to receive and mate with complementary threaded fasteners, such that the fasteners frictionally engage the barrel nut and provide a mechanical mounting lock.

According to another embodiment of the invention, a second pair of cavities are formed on opposite sides of the rail section proximate the exit end, and the cavities are counterbored and threaded to receive and mate with complementary threaded fasteners.

According to another embodiment of the invention, a firearm assembly comprises an upper receiver comprising a firearm barrel, a firearm handguard having an elongate rail section and defining opposed receiving and exit openings, and the barrel is positioned through the receiving and exit openings. A barrel nut is mounted on the firearm barrel, and includes a first end and an opposed second end. Attachment means are proximate the first end for attaching the barrel nut to the upper receiver. The attachment means can be threads formed on the interior surface of the barrel nut that engage complementary threads on the upper receiver. A transverse groove is formed on an exterior surface of the barrel nut between the first end and the second end. The handguard is positioned over the barrel nut, and the transverse groove mechanically engages the firearm handguard on the barrel nut.

According to another embodiment of the invention, the handguard includes a lug proximate the receiving end whereby the lug engages the upper receiver and minimizes movement of the handguard.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an environmental perspective view of an attachment assembly for a firearm handguard according to a preferred embodiment of the invention;

FIG. 2 is a partial perspective view of the attachment assembly of FIG. 1;

FIG. 3 is an exploded perspective view of the attachment assembly of FIG. 1;

FIG. 4 is a partial side view of the attachment assembly of FIG. 1;

FIG. 5 is a perspective view of the barrel nut of the attachment assembly of FIG. 1, shown mounted on a firearm barrel;

FIG. 6 is a partial perspective view of the attachment assembly of FIG. 1;

FIG. 7 is a side view of the barrel nut of the attachment assembly of FIG. 1;

FIG. 8 is another environmental perspective view of the attachment assembly of FIG. 1;

FIG. 9 is a front elevation of the receiving end of the handguard of the attachment assembly of FIG. 1;

FIG. 10 is another front elevation of the receiving end of the handguard of the attachment assembly of FIG. 1;

FIG. 11 is a side view of the handguard of the attachment assembly of FIG. 1;

FIG. 12 is a side view of a quick disconnect insert of the attachment assembly of FIG. 1;

FIG. 13 is a partial exploded view of the attachment assembly of FIG. 1;

FIG. 14 is another partial exploded view of the attachment assembly of FIG. 1;

FIG. 15 is a partial perspective view of the attachment assembly of FIG. 1;

FIG. 16 is another partial perspective view of the attachment assembly of FIG. 1; and

FIG. 17 is an environmental perspective view of the attachment assembly of FIG. 1 on a firearm.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION AND BEST MODE

An attachment assembly for a firearm handguard according to a preferred embodiment of the invention is illustrated in FIGS. 1-3, and shown generally at reference numeral 10. As shown in FIG. 3, the handguard attachment assembly 10 comprises a barrel nut 50 for attaching a handguard 20 to a firearm's upper receiver 100. The handguard 20 includes an elongate rail section 22 with an open receiving end 24 and an open exit end 26, located at opposite longitudinal ends of the rail section 22.

As shown in FIGS. 5 and 6, the barrel nut 50 is mounted on the barrel 102 of the firearm upper receiver 100. Preferably, the barrel nut 50 is made of steel and can be about 0.875 inch to 8.000 inches in length. Most preferably, the barrel nut 50 is two inches long. As shown in FIGS. 6 and 7, the barrel nut 50 comprises a first section 52 having interior female threads for mating with male threads of the firearm's upper receiver 100. A second section 56 of the barrel nut 50 receives the firearm barrel 102. The exterior of the second section 56 has a knurled surface, and a transverse radial groove 54 is formed in between the first section 52 and the second section 56 of the barrel nut 50.

The handguard 20 is positioned over the firearm barrel 102, with the barrel 102 extending through the receiving end 24 and through the exit end 26, as shown in FIGS. 1 and 8. The receiving end of the handguard 24 is pushed over barrel nut 50. The transverse radial groove 54 of the barrel nut 50 provides a mechanical lock for attachment of the handguard 20 to the firearm's upper receiver 100, and the knurled exterior surface 56 of the barrel nut 50 facilitates frictional engagement at the interface of the handguard 20 with the barrel nut 50. As shown in FIGS. 9 and 10, the handguard 20 includes a deep lug 28 formed in the receiving end 24 that provides a mechanical, anti-rotation lock when the receiving end 24 is interfacing and indexing with the upper receiver 100 of the firearm. The lug 28 is preferably machined into the receiving end 24 at a depth of about 0.125 inch.

As shown in FIGS. 11, 13 and 14, a pair of cavities 34 are formed on opposite sides of the rail section 22 of the handguard 20 proximate the receiving end 24. Likewise, a second pair of threaded cavities, 36 are formed on opposite sides of the rail section 22 proximate the exit end 26. Each of the cavities 34, 36 can be counterbored and threaded to receive and mate with a threaded fastener such as a quick disconnect thumbscrew (QD insert) 32. Preferably, the exterior surface of each cavity 34, 36 is comprised of aluminum, and each QD insert is made of steel. The QD inserts 32 are screwed into cavities 34 located at the receiving end 24, and frictionally engage the barrel nut 40 to provide a mechanical mounting lock that securely maintains the handguard 20 in firm attachment to the firearm barrel 102. The QD inserts 32 also provide a location for a QD sling attachment. The QD insert 32 can allow for both types of commercially available QD locks.

The attachment assembly 10 can be used with automatic and semi-automatic rifles, including the M-16, AR-15 and AR-10 rifles.

An attachment assembly for a firearm handguard and a method of attaching a handguard to a firearm are described above. Various changes can be made to the invention without departing from its scope. The above description of the preferred embodiments and best mode of the invention are provided for the purpose of illustration only and not limitation—the invention being defined by the following claims and equivalents thereof. 

1. An attachment assembly for a firearm handguard comprising a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon, the barrel nut comprising: (a) a first end for engaging an upper receiver of a firearm; (b) a second end opposite the first end for receiving the firearm handguard; and (c) a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the transverse groove mechanically engages the firearm handguard on the barrel nut.
 2. An attachment assembly according to claim 1, wherein the barrel nut includes an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver.
 3. An attachment assembly according to claim 2, wherein the barrel nut threads are female threads, and the upper receiver threads are male.
 4. An attachment assembly according to claim 1, wherein the barrel nut has a length of 0.875 inch to 8.000 inches.
 5. An attachment assembly according to claim 1, wherein the barrel nut has a length of about two inches.
 6. An attachment assembly according to claim 1, wherein the barrel nut includes a knurled section formed on the exterior surface of the barrel nut proximate the second end, wherein the knurled section facilitates frictional engagement at the interface of the barrel nut and the handguard.
 7. An attachment assembly according to claim 6, wherein the transverse groove is formed on the exterior surface of the barrel nut between the first end and the knurled section, and the knurled section is formed on the exterior surface between the transverse groove and the second end.
 8. An attachment assembly for a firearm comprising a firearm handguard comprising: (a) an elongate rail section for a user to grip the handguard; (b) an open exit end for allowing a firearm barrel to exit therethrough; (c) an open receiving end opposite the exit end for positioning over a barrel nut mounted on a firearm barrel, and mating with an upper receiver of the firearm, wherein a lug is formed on the receiving end whereby the lug provides a mechanical, anti-rotation lock when the handguard interfaces with the upper receiver.
 9. An attachment assembly according to claim 8, wherein the lug is formed in the receiving end at a depth of about 0.125 inch.
 10. An attachment assembly according to claim 8, further comprising a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon, the barrel nut comprising: (a) a first end for engaging an upper receiver of a firearm; (b) a second end for receiving the firearm barrel and the firearm handguard; and (c) a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the transverse groove mechanically engages the firearm handguard on the barrel nut.
 11. An attachment assembly according to claim 10, wherein the barrel nut includes an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver.
 12. An attachment assembly according to claim 10, wherein the barrel nut includes a knurled section formed on the exterior surface of the barrel nut proximate the second end, wherein the knurled section facilitates frictional engagement at the interface of the barrel nut and the handguard.
 13. An attachment assembly according to claim 12, wherein the transverse groove is formed on the exterior surface of the barrel nut between the first end and the knurled section, and the knurled section is formed on the exterior surface between the transverse groove and the second end.
 14. An attachment assembly according to claim 10, wherein at least one cavity is formed in the rail section of the handguard proximate the receiving end, wherein the cavity is threaded to receive and mate with a complementary threaded fastener, whereby the fastener frictionally engages the barrel nut and provides a mechanical mounting lock.
 15. An attachment assembly according to claim 14, wherein an exterior surface of the cavity is comprised of aluminum, and the complementary threaded fastener comprises a steel quick disconnect thumbscrew insert.
 16. An attachment assembly according to claim 15, wherein a quick disconnect sling is attached to the quick disconnect thumbscrew insert.
 17. An attachment assembly according to claim 10, wherein a first pair of cavities are formed on opposite sides of the rail section proximate the receiving end, wherein the cavities are counterbored and threaded to receive and mate with complementary threaded fasteners, whereby the fasteners frictionally engage the barrel nut and provide a mechanical mounting lock.
 18. An attachment assembly according to claim 17, further comprising a second pair of cavities are formed on opposite sides of the rail section proximate the exit end, wherein the cavities are counterbored and threaded to receive and mate with complementary threaded fasteners.
 19. A firearm assembly comprising: (a) an upper receiver comprising a firearm barrel; (b) a firearm handguard comprising an elongate rail section and defining opposed receiving and exit openings, wherein the barrel is positioned through the receiving and exit openings; (c) a barrel nut mounted on the firearm barrel and comprising a first end and an opposed second end, attachment means proximate the first end for attaching the barrel nut to the upper receiver, and a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the handguard is positioned over the barrel nut and the transverse groove mechanically engages the firearm handguard on the barrel nut.
 20. A firearm assembly according to claim 19, wherein the handguard comprises a lug proximate the receiving end whereby the lug engages the upper receiver and minimizes movement of the handguard. 